$.fn.form2json = function(){
	var formId = $(this).attr("id");
	var t = (new Date()).valueOf();
	var serializedParams = this.serialize() + '&t='+ t +'&sign=' + hex_md5(qkb.pubFun.serialize(formId)+ '&' + t);
	var obj = qkb.pubFun.paramStringToObj(serializedParams);
	return qkb.pubFun.ObjToStr(obj);
}